Powder beds are commonly used in laser bed additive manufacturing techniques. These techniques generally require a step of providing a thin layer of powder over a build plate within the additive manufacturing apparatus. In one example, a powder dispenser 101 is provided that pushes an amount of powder (e.g., CoCr) upward into the build chamber where a roller or arm 102 spreads the powder over the build plate 103. FIG. 1. A laser heats the powder in a desired pattern corresponding to a cross section of a part, sintering or melting the powder to form a solid cross section slice on the build plate 103. The build plate is lowered and the powder dispenser and roller or arm redistributes a thin layer of powder over the build plate. The laser then heats the powder building on the earlier deposited pattern of fused material, thereby making successive layers in the additive manufacturing process.
Another way that a thin layer of powder is provided upon a build plate is through a powder hopper 201 used in conjunction with a recoater arm/temporary hopper 202. FIG. 2. The recoater arm/temporary hopper 202 spreads a thin layer of powder over the build plate 203 by moving across the build plate and dropping powder in a controlled manner to provide a thin layer of powder. This process is repeated with each laser writing step and lowering of the build plate in the additive manufacturing process.
The existing technology requires a time consuming step of providing a thin uniform layer of powder over a horizontal build plate using either recoater arm and/or a hopper. There is a need in the art for a higher throughput higher uniformity additive manufacturing process and apparatus.